Optical couplers, such as connectors and splices, are a vital part of the total fiber optic communications network. These devices help determine whether the fiber optics loop will have sufficient cost efficiency and technical efficiency to become more widely used by subscribers.
Optical fibers may be joined to each other by either fusion or mechanical splices. Mechanical splices are defined as those splices which are not fusion splices. An index matching material such as a grease or gel is used in many splices to minimize Fresnel losses.
The technical literature has addressed concerns that fiber optic mechanical splices may experience erratic losses and reflectance due to particulate occlusion. Such occlusion occurs when air bubbles or dust particles become trapped around the junction point between optical fibers in a mechanical splice. Since .air bubbles in the index matching material used in mechanical splices are undesirable, it has been suggested to subject such materials to a vacuum after mixing, and to use high viscosity materials as components of index matching materials.
Because index matching materials are imperfect, it is believed that a need exists for fiber optic mechanical splices designed to ameliorate the problem of air bubbles in index matching materials.